I am trying to extract a baseband from a wideband spectrum. For this purpose I have tried using both the 'Frequency Xlating FIR Filter' and the 'Frequency Xlating FFT Filter' (screenshot of the flowpragh is attached).

The problem that I have encountered is that upon changing the centre frequency of the Xlating Filter using a slider, each time the signal(recording of a 5M spectrum being received from another USRP) appears on a different frequency than it was originally observed.